This invention relates to a throttle linkage system and more particularly to an improved linkage system for synchronizing the movement between a plurality of throttle valves.
In many applications of internal combustion engines having a plurality of induction passages each induction passage is served by a respective throttle body in which a throttle valve is positioned. For example, it is typical with multi-cylinder engines to employ plural carburetors all affixed to a common manifold and which have individual throttle valves. Obviously, it is desirable to have all of the throttle valves operated in unison and it has been practiced to provide a throttle actuator which is connected to the throttle valve of one of the throttle bodies and that throttle valve is connected to the remaining throttle valves through a linkage system. However, there are some disadvantages with the types of systems previously proposed.
Frequently, the throttle bodies are affixed to an intake manifold or other portion of the engine which is formed from a lightweight material such as aluminum or an aluminum alloy. However, the throttle linkage for the synchronization of the throttle valves may use interconnecting links or a single link formed from a more corrosion-resistant material such as stainless steel. As a result of this arrangement, the different thermal expansion between the throttle bodies and the linkage system can cause discrepancies in the positions of the throttle valves which are not desirable.
In addition to these disadvantages, the inherent structure is such that the alignment of the individual throttle bodies and interconnecting member may not be completely accurate. In addition, the throttle valves are interconnected by a system of levers that are affixed to the throttle valve shafts and which contain at their outer extremities pins that are received in bores in the interconnecting linkage. However, due to manufacturing variations the pin and bore relationship may not be exact. Such misalignments can cause binding in not only the throttle linkage but also in the throttle valve shaft itself that presents obvious difficulties.
It is, therefore, a principal object of this invention to provide an improved throttle linkage system for synchronizing a plurality of throttle valves.
It is a further object of this invention to provide a throttle linkage system for synchronizing a plurality of throttle valves for an engine and wherein the synchronization can be maintained without concern for different thermal expansions.
It is a further object of this invention to provide an improved and simplified throttle linkage system for an engine wherein misalignment can be tolerated without upsetting the synchronization of the individual throttle valves.